Presently, the World Health Organization (WHO 2018) reported that 844 million people worldwide cannot access adequate basic drinking-water service. Consequently, the UN Environment's (2019) sixth Global Environment Outlook report revealed that inaccessibility of clean water causes 1.4 million premature deaths annually due to pathogens and toxic chemicals from unsustainable waste and wastewater management. The same report also pointed out that over 80% of the world's wastewater and over 95% in some least developed countries is currently released into the environment without treatment, causing both surface water and groundwater contamination. Thus, appropriate treatment of wastewater before being discharged to the environment is essentially the key to securing public health and quality of life.

Moreover, water decontamination is needed for correcting unintended consequences of past improper practices. As of 2018, 1,566 contaminated sites have been listed on the National Priority List (NPL) in the USA, and...